The squadron was officially announced in August 1918 and was to be formed at Gibraltar from three former RNAS flights 364, 365, and 366 to perform anti-submarine patrols. There is no evidence that the squadron actually formed and this may have been because of the war ending on 11 November. Sources say it was either officially disbanded in January 1919 or abandoned.
U-197 was caught on the surface 240 miles south of Madagascar by Catalina FP-126 of 259 Squadron on 20 August 1943. Damaged by machine gun fire and depth charges from the plane, the U-boat was forced to remain on the surface. Catalina FP-313 of 265 Squadron flown by Flying Officer C. Ernest Robin was called to attack, sinking the U-boat with all hands by depth charges.
U-862
On 20 August 1944Flight LieutenantWilliam Stewart Lough's Catalina FP104/H caught German submarine U-862 on the surface in the Mozambique Channel and attacked it. A depth charge was dropped but missed and the Catalina was hit by fire from the submarines anti-aircraft gun. The plane flew back over the submarine and crashed into the sea in front of it. The submarine recovered the planes log book, which showed it had been looking for a missing ship either the Empire City or Empire Day which had been sunk by U-198 on 5 August. None of the planes 9 crew and 4 passengers had survived. U-862 escaped unharmed to join the Monsun Gruppe based at Penang.
Disbandment
Towards the end of the war the units focus shifted from submarine hunting to moving freight. The squadrons disbandment date is as clouded as its founding date: sources cite 18 April 1945; 30 April 1945 or 1 May 1945. Its final patrol was on 12 April 1945.